Oscillating-current generator.



L. DE FOREST. OSCILLATING CURRENT GENERATOR.

APPLICATION FILED mmzs. m5.

L%1.,@M.. Patented Apr. 3,1917.

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LEE DE EoEEs'r, or NEW YoEK, N. Y., Assre'NoE r DE EoEEsr RADIOTELEPHONE AND TELEGRAPH coMrANY, on NEW YoEK, N. Y., A CORPORATION orDELAWARE.

OSCILLATING-GURRENT GENERATOR.

zen of the United States, and residing at New York, county of Bronx,State of New York, have made a certain new and useful Invention ,inOscillating-Current Gienerators, of which the following is aspecification.

This invention relates to oscillating current generators.

The object of the invention is to provide a high frequencyoscillatingcurrent generator which is simple and efficient.

Other objects of the invention will appear more fully hereinafter.

The invention consists substantially in the construction, combination,location and relative arrangement of parts all as will be more fullyhereinafter set forth, as shown in the accompanying drawings, andfinally pointed out in the appended claims.

Figure 1 is a circuit diagram showing one arrangement embodying minvention.

Figs. 2 and 3 are modi 'ed constructions of oscillation generatorsembodying my in-.

vention. v

Fig. 4 is a sectional view taken on the line 4-4, Fig. 1, and looking inthe direc-- tion of the arrows.

It is among the special purposes of my present invention to providemeans for generating oscillating currents, and to so assoable resistance8 to the electrodes 5, 6, to

heat the same and cause a vapor arc column to form in the passage 4.

In a chamber 23*, forming part of the evacuated vessel 1 andcommunicatin with the mercury arc passage 4, are locate ,two'coldelectrodes 9 and 10, preferably arranged at different distances from thevapor arc 'column maintained in the'passagel.

4 The electrode 9 is electrically connected- Specification of LettersPatent. Patented Apr. 3, 1191].? Application filed March 26, 1915,Serial No. 17,225. I

td one terminal of a source of electroiiidtive force 11. I have found itpreferable to employ a direct current generator, as shown,

but my invention is not to be limited thereto. One termmal of thecurrent source 11 is connected'to an electrode 9, and the other terminalof said current source 11 is connectplished in any suitable convenientmanner.

In the case of electrode 9 I have shown a simple arrangement wherein Iemploy a reservoir 13 which is provided with pipes 14;

opening upon the electrode 9 and adapted to projecting out of saidevacuated vessel 1 toallow a cooling medium to circulate therethrough.My invention, however, is not to be limited or restricted in thisrespect.

In the usual and well known way, I as sociate an oscillating circuitwith the two cold electrodes 9 and 10. This circuit consists of theusual condenser 15, and inductance 16, arranged in series withelectrodes 9 and 10 and with each other. and as shown, a switch or otherform of circuit make and break device 17 may also be placed in seriesinthis oscillating circuit.

If desired, and as shown, a variable capacity, such as a condenser 18-,may be shunted around the inductance 16, but my invention 9'0 Ifdesired,

in its broad'scope is not to be limited or re electrodes. The purpose ofthis leak path is tov conduct off the excessive charge which maycumulate on the electrode 10 and the" ,1 reduce the efficient operationof the osci'l ato aa I have discovered that if a second oscil:

lating circuit be established including therethe electrode 9 and thevaporarc main-- tained in the passage 4, the inductance and condenser 21all in' series with each other the oscillations set up in the originaloscillating circuit 9, 16, 18, 15, 10, are increased 111 intensityprovided the period of the. second oscillating circuit is made equalspect therefore, the elements20, 21, may be omittedif desired. ,When thetwo oscillating circuits are employed, however, the inductance elements'16, 20,- thereof, should be inductively associated.

A load or output circuit maybe associated, either inductively orconductively with one or both of the above described os- ,cillatingcircuits. In the arrangement shown, the load circuit is made up of avariable inductance 22 connected intermediate the radiating antenna 23and the ground or earth 24 in the usual and well known manner for radiooperation; The natural period of the load circuit should be equal tothat of the-first cuit.

In Fig. 2 I show a modified form of evacuated vessel oscillator, whereinthe heated electrode may be a filament instead of a i vapor arc abovedescribed. In this form of my invention the cold electrode 10 is shownin' section as a metal tube inserted inthe constricted portion of thechamber 3 -of the vessel 1, immediately above the passage 4.

Instead of employing a column of vapor, if desired, and as shown, aheavy filamentof tungsten or platinum coated with oxidof I calcium.;.orother suitable material may be employed asindicated at 25. In this in-.

- stance, heavy leading in wires. 26 are em- I h this modification of myinvention is simishown in Fig. l.

ployed tosupport the heating filament 25. The circuit connections andtheoperation of lar to the above described arrangement I If desired,instead of employing the merwith a suitable non-vaporizable electrodesuch as indicated at 2'7, Fig.3, I I Theexact operation involved in ageneratorhaving the construction shown in the feed chambers. 2, 3 ofFig. 1, or the filament arrangement of Fig. 2, one of the chambers 2, 3,may be supplied with a mercury. or'other form of electrode such as 5 or6, while'the rawing, and as above described I have not r as'yet beenable to fully and 'eompletely unoperate" as a or original oscillatingcir- If the generator 11 is a direct current .source a negative currentisset up across the oscillator by means of the thermions-pass ing fromthe hot electrode 25, 27, or the vapor arc in passage 4 as the case maybe, to the cold electrode 9. A charge impressed upon the cold electrode10 will greatly reduce the flow of thermions from the hot electrode orvapor arc to the electrode 9, or, in other words, will increase thepotential drop between the cold electrode 9 and the hot electrode.Therefore, if the electrical connec- 4. tion between the electrode 10and the electrode 9' be suddenly established by closing the switch orcircuit maker 17, the positive potential of the electrode 9 and. of thepositive terminal of condenser 18 will be suddenly increased. Further,any positive charge on the. electrode 10 will be rapidly carried away byaction of charged thermions from the hot electrode attractedthereto,inasmuch as the capacity of the stopping condenser 15 is small. Thus adifference in potential is quickly established between denser 18. Theinductance coil 16 prevents this difference of potential across the.condenser 18 from immediately equalizing and minal of condenser 18, andon the electrode I the negatively the two terminals of con 9 causes asudden increase of positive current from source 11 which again chargesone negative current again sets up across coil 16 to the otherterminalof said condenser cury or other form of electrodes 6, 5 in thehot electrode to the cold electrode 9,

that is, will again still further increase the I terminal of saidcondenser. Thuscondenser other assoclated chamber may be provided 18will once more begin to discharge a positive current through the, coil16 and the en- .tire phenomena as above described, willbe 'ceeds,coil16, up to a point where the losses inthe q h circuits and in theoscillator are equal to any xderstand. I have discovered however thatsuch an arrangement or arrangements do I generator ofh ghfrequency1o'sc1llat1 ons' suitable fOI'TfltilQ'WQIk and, -'ture' of my invention,and various arrange- Having now described the objects and naterminal ofcondenser 18 positively, and a .further increasein the energyrepresenting the'oscillations.

nearest ments for accomplishing the same, what I claim as new and usefuland desire to secure by LettersPatent, is,-

I. In a system for generating oscillating current, a work circuit, andmeans for generating and transmitting the generated oscillations to saidwork circuit comprising a vapor arc and a'plurality of cold electrodes,each located at a relatively difi'erent distance from said arc and eachdirectly conductively connected to said work circuit, and means vforsuccessively charging one of said cold electrodes.

2. In a system for generating oscillating current, a work circuit, andmeans for generating and transmitting the generated oscillations to saidwork circuit comprising a vapor arc and a plurality of cold electrodes,each located at a relatively diflerent distance from said arc, a'seriesoscillating circuit connecting said cold electrodes, and means forimpressing an electromotive force upon the electrode in the spacebetween said are and the other cold electrode.

3. In asystem for generating electrical oscillations, a work circuit,and means for generating and transmitting the generated oscillationscomprising a vapor arc and a cold anode, a source of electromotive forcein series relation between said vapor arc and anode, a second anode, anda series oscillating circuit connecting said anodes.

4. An oscillator for generating high frequency oscillations comprisingan evacuated vessel and a vapor arc. and two cold electrodes containedtherein, av current source connected between one of said cold electrodesand the vapor arc, and a series oscil lating circuit connected betweensaid cold electrodes to set up an alternating current therebetween, awork circuit and means to transmit the generated osc'llations to saidcircuit.

5. An oscillating system consisting of a vapor arc and a cold anode, asource of electromotive force in series circuit relation between saidvapor arc and anode, a secondanode, and a series oscillating circuitconnecting said anodes, a work circuit, and means to transmit thegenerated oscillations to said .WOI'k circuit.

6. An oscillating system consisting of a heated cathode and a coldanode, a source of electromotive force in series circuit relationbetween said cathode and anode, a second anode, and a series oscillatingcircuit connecting said anodes, and a second oscillating circuitassociated with said first mentioned oscillating circuit, an antennasystem, and means for transmitting the generated oscillations to saidantenna system.

In testimony whereof I have hereunto set.

my hand witnesses, 1915.

in the presence of the subscribing on this 24th day of March A. D.,

LEE D'E FonEs'r.

